diff options
Diffstat (limited to 'drivers/phy/phy-can-transceiver.c')
| -rw-r--r-- | drivers/phy/phy-can-transceiver.c | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/drivers/phy/phy-can-transceiver.c b/drivers/phy/phy-can-transceiver.c new file mode 100644 index 000000000..840b7f8a3 --- /dev/null +++ b/drivers/phy/phy-can-transceiver.c @@ -0,0 +1,174 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * phy-can-transceiver.c - phy driver for CAN transceivers + * + * Copyright (C) 2021 Texas Instruments Incorporated - https://www.ti.com + * + */ +#include <linux/of.h> +#include<linux/phy/phy.h> +#include<linux/platform_device.h> +#include<linux/module.h> +#include<linux/gpio.h> +#include<linux/gpio/consumer.h> +#include <linux/mux/consumer.h> + +struct can_transceiver_data { + u32 flags; +#define CAN_TRANSCEIVER_STB_PRESENT BIT(0) +#define CAN_TRANSCEIVER_EN_PRESENT BIT(1) +}; + +struct can_transceiver_phy { + struct phy *generic_phy; + struct gpio_desc *standby_gpio; + struct gpio_desc *enable_gpio; + struct mux_state *mux_state; +}; + +/* Power on function */ +static int can_transceiver_phy_power_on(struct phy *phy) +{ + struct can_transceiver_phy *can_transceiver_phy = phy_get_drvdata(phy); + int ret; + + if (can_transceiver_phy->mux_state) { + ret = mux_state_select(can_transceiver_phy->mux_state); + if (ret) { + dev_err(&phy->dev, "Failed to select CAN mux: %d\n", ret); + return ret; + } + } + if (can_transceiver_phy->standby_gpio) + gpiod_set_value_cansleep(can_transceiver_phy->standby_gpio, 0); + if (can_transceiver_phy->enable_gpio) + gpiod_set_value_cansleep(can_transceiver_phy->enable_gpio, 1); + + return 0; +} + +/* Power off function */ +static int can_transceiver_phy_power_off(struct phy *phy) +{ + struct can_transceiver_phy *can_transceiver_phy = phy_get_drvdata(phy); + + if (can_transceiver_phy->standby_gpio) + gpiod_set_value_cansleep(can_transceiver_phy->standby_gpio, 1); + if (can_transceiver_phy->enable_gpio) + gpiod_set_value_cansleep(can_transceiver_phy->enable_gpio, 0); + if (can_transceiver_phy->mux_state) + mux_state_deselect(can_transceiver_phy->mux_state); + + return 0; +} + +static const struct phy_ops can_transceiver_phy_ops = { + .power_on = can_transceiver_phy_power_on, + .power_off = can_transceiver_phy_power_off, + .owner = THIS_MODULE, +}; + +static const struct can_transceiver_data tcan1042_drvdata = { + .flags = CAN_TRANSCEIVER_STB_PRESENT, +}; + +static const struct can_transceiver_data tcan1043_drvdata = { + .flags = CAN_TRANSCEIVER_STB_PRESENT | CAN_TRANSCEIVER_EN_PRESENT, +}; + +static const struct of_device_id can_transceiver_phy_ids[] = { + { + .compatible = "ti,tcan1042", + .data = &tcan1042_drvdata + }, + { + .compatible = "ti,tcan1043", + .data = &tcan1043_drvdata + }, + { + .compatible = "nxp,tjr1443", + .data = &tcan1043_drvdata + }, + { } +}; +MODULE_DEVICE_TABLE(of, can_transceiver_phy_ids); + +static int can_transceiver_phy_probe(struct platform_device *pdev) +{ + struct phy_provider *phy_provider; + struct device *dev = &pdev->dev; + struct can_transceiver_phy *can_transceiver_phy; + const struct can_transceiver_data *drvdata; + const struct of_device_id *match; + struct phy *phy; + struct gpio_desc *standby_gpio; + struct gpio_desc *enable_gpio; + u32 max_bitrate = 0; + int err; + + can_transceiver_phy = devm_kzalloc(dev, sizeof(struct can_transceiver_phy), GFP_KERNEL); + if (!can_transceiver_phy) + return -ENOMEM; + + match = of_match_node(can_transceiver_phy_ids, pdev->dev.of_node); + drvdata = match->data; + + if (of_property_read_bool(dev->of_node, "mux-states")) { + struct mux_state *mux_state; + + mux_state = devm_mux_state_get(dev, NULL); + if (IS_ERR(mux_state)) + return dev_err_probe(&pdev->dev, PTR_ERR(mux_state), + "failed to get mux\n"); + can_transceiver_phy->mux_state = mux_state; + } + + phy = devm_phy_create(dev, dev->of_node, + &can_transceiver_phy_ops); + if (IS_ERR(phy)) { + dev_err(dev, "failed to create can transceiver phy\n"); + return PTR_ERR(phy); + } + + err = device_property_read_u32(dev, "max-bitrate", &max_bitrate); + if ((err != -EINVAL) && !max_bitrate) + dev_warn(dev, "Invalid value for transceiver max bitrate. Ignoring bitrate limit\n"); + phy->attrs.max_link_rate = max_bitrate; + + can_transceiver_phy->generic_phy = phy; + + if (drvdata->flags & CAN_TRANSCEIVER_STB_PRESENT) { + standby_gpio = devm_gpiod_get_optional(dev, "standby", GPIOD_OUT_HIGH); + if (IS_ERR(standby_gpio)) + return PTR_ERR(standby_gpio); + can_transceiver_phy->standby_gpio = standby_gpio; + } + + if (drvdata->flags & CAN_TRANSCEIVER_EN_PRESENT) { + enable_gpio = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_LOW); + if (IS_ERR(enable_gpio)) + return PTR_ERR(enable_gpio); + can_transceiver_phy->enable_gpio = enable_gpio; + } + + phy_set_drvdata(can_transceiver_phy->generic_phy, can_transceiver_phy); + + phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate); + + return PTR_ERR_OR_ZERO(phy_provider); +} + +static struct platform_driver can_transceiver_phy_driver = { + .probe = can_transceiver_phy_probe, + .driver = { + .name = "can-transceiver-phy", + .of_match_table = can_transceiver_phy_ids, + }, +}; + +module_platform_driver(can_transceiver_phy_driver); + +MODULE_AUTHOR("Faiz Abbas <faiz_abbas@ti.com>"); +MODULE_AUTHOR("Aswath Govindraju <a-govindraju@ti.com>"); +MODULE_DESCRIPTION("CAN TRANSCEIVER PHY driver"); +MODULE_LICENSE("GPL v2"); |